Descriptive method of characters for displaying the thickness of strokes thereof

ABSTRACT

The present invention employs the notion of a Chinese writing brush moving a geometric figure to produce a style of calligraphy, and the area of the geometric figure is big or small, then the strokes of a character is also big or small. Hence the purpose that is the variance of the strokes of a character achieved using the present invention. The present invention only decides the moving path of the strokes of a character and the size of the geometric figure from the starting points and the end points, and then moves the geometric figure along the moving path, the area the geometric figure passing is the style of calligraphy.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a descriptive method of characters, andmore particularly to a descriptive method of characters for displayingthe thickness of strokes thereof.

[0003] 2. Description of the Prior Art

[0004] In general, the fonts produced by descriptive methods ofcharacters comprise three types: bitmap font, outline font, vector font,respectively. The three types of descriptive methods of characters willbe described below.

[0005] 1. Bitmap Font: The descriptive method of bitmap font isdisplayed with pixels. As shown is FIG. 1A, the area 2 with obliquelines displayed in the area of the font and the white area 4 withoutoblique lines is displayed in the outer area of the font. Therefore, thebitmap font is an image of the font and displayed the form of a fontaccurately in the fixed size of the font. Furthermore, the bitmap fonteasily displays characters in a monitor. But, the disadvantage is thatthe data of the font is very large. Moreover, due to the bitmap fontbeing an image and the size of the bitmap font being fixed, a resizedfont has a problem with distortion. Hence, the bitmap font is not fitfor resizing and the resized font is not refined and beautiful.

[0006] 2. Outline Font: As shown in FIG. 2A and FIG. 2B, the outlinefont is described by means of curves and strokes controlled by controlpoints 8. The outline 10 of the font is described by the curves. Thearea surrounded by the curves is the form of the font, as shown in FIG.1B. In general, the bend of the outline 10 thereof is displayed with aquadratic curve (two-order function) or a cubic Bézier curve(three-order function). Furthermore, the curves of the outline font aredescribed by the stroke thickness of the font. Because the bend of theoutline 10 and the thickness of strokes, the font can be describedexquisitely with the starting and ending control point 6, and controlpoint 8, the outline font is refined and beautiful. Moreover, comparedwith the bitmap font, the data of the font is less and the resizedoutline font is still refined and beautiful as well as the originaloutline font. Therefore, the outline font is a popularly font, e.g.TrueType Font PostScript. A general set of a Chinese, Japanese, orKorean (CJK) fonts is about 7,000˜18,000 characters and a set of thesefonts are about 5˜12 Million bytes. Regarding a PDA (Personal DigitalAssistant), Set-Top Box, and a cellular phone, the amount of thecharacters in these apparatuses is limited due to the limitation ofmemory.

[0007] 3. Vector Font: The vector font is described by the means ofcentral curves and strokes controlled by control points 8, as shown inFIG. 1C. Due to the lack of form, description and a thickness ofstrokes, the vector font limits the font to a lightface or boldface.Therefore, the appearance of the font is not refined and beautiful asthe outline font. However, the data of the vector font is mainly thecentral curves of the strokes without describing the variant of the formof characters. Hence, the amount of the data thereof can be efficientlyreduced. Compared with the bitmap font and the outline font, the amountof the data thereof is minimum. Moreover, the resized font can beperformed without distortion.

[0008] The current trend of development of Information Appliance ismobile and exquisite, however, the memory limitation in a device willresult in a serious problem. Hence, it needs a new descriptive method ofcharacters, not only saves more characters under the limitation ofmemory and the low-resolution of display screens, but also to transmitthe characters through a limited bandwidth in a shorter time. Thepresent invention can overcome the aforementioned disadvantages todescribe refined characters and economize on memory.

SUMMARY OF THE INVENTION

[0009] In the conventional arts, a larger number of data is needed todescribe refined characters or it limits characters to a lightface orboldface with less data that cannot describe the variants in thethickness of characters. Based on the previous mentioned embodiments, itis an objective for the present invention to provide a descriptivemethod of characters for displaying the thickness of strokes thereofwith less data.

[0010] It is another objective for present invention to provide adescriptive method of characters for displaying the thickness of strokesthereof which reduces the amount of data. Therefore, more characters andtypes of characters can be saved under the memory limitation and themore complicated Chinese, Japanese, or Korean (CJK) fonts can betransmitted.

[0011] It is a still another objective of the present invention toprovide a descriptive method for displaying the stroke thickness ofcharacters thereof to display the characters in a screen readily andrefined.

[0012] It is another objective of the present invention to provide adescriptive method for displaying the stroke thickness of charactersthereof, so that a user can use exquisite and varied characters.

[0013] As aforementioned, the present invention provides a descriptivemethod for displaying the stroke thickness of characters thereof. Thedescriptive method can decide at least one moving path of the characteraccording to the characteristics of at least one stroke, decide upon thedimension of the geometric figure at a plurality of control point. Thisis achieved according to the characteristics and thickness of the atleast one stroke, and the path of movement along the center of thegeometric figure which varies the dimension of the geometric figure toform the character. The present invention also provides a method forcomposing font. The method forms a database comprising of at least onecommon basic stroke for at least one character. Wherein a descriptivemethod of the at least one common stroke for the at least one characterof the database is comprised of the following. At least one moving pathof the character must be decided according to the characteristics of theat least one common basic stroke of the at least one character of thedatabase. Deciding upon a dimension of the geometric figure at aplurality of control points, according to the characteristics of thethickness of at least one basic stroke; and the movement at the centerof the geometric figure along at least one moving path and the varyingdimension of the geometric figure to form the character. The presentinvention further provides an apparatus for descriptive font. Theapparatus comprises an assembly deciding at least one moving path of thecharacter according to characteristics of the at least one stroke. Anassembly deciding a dimension of the geometric figure at a plurality ofcontrol point according to characteristics of the thickness of the atleast one stroke. And an assembly moving towards the center of thegeometric figure along at least one moving path varying the dimension ofthe geometric figure to form the character is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The foregoing aspects and many of the attendant advantages ofthis invention will become more readily appreciated as the same becomesbetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

[0015]FIG. 1A to FIG. 1C is a diagram of the bitmap font, the outlinefont, and the vector font, respectively;

[0016]FIG. 2A to FIG. 2B is a curve described by a quadratic equationand a cubic equation, respectively;

[0017]FIG. 3 is a diagram of a circle moving along a moving path;

[0018]FIG. 4A is a radius of a circle described by a cubic equation;

[0019]FIG. 4B is a stroke described by a parameter of a radius of acircle;

[0020]FIG. 4C is a diagram of a stroke passed by a circle;

[0021]FIG. 4D is a diagram of a complicated stroke

[0022]FIG. 5A to FIG. 5D is a character by means of the presentinvention;

[0023]FIG. 6A to FIG. 6H is the comparison of the Chinese writing brushfont, the outline font, and the vector font.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0024] Some sample embodiments of the invention will now be described ingreater detail. Nevertheless, it should be recognized that the presentinvention can be practiced in a wide range of other embodiments, besidesthose explicitly described, and the scope of the present invention isexpressly not limited expect as specified in the accompanying claims.

[0025] The concept of a Chinese writing brush is employed by the presentinvention, which a stroke becomes thicker as more force is applied andthe stroke becomes thinner as the force on the Chinese writing brush isweakened. Therefore, the main concept of the present invention is tocontrol the dimension of a geometric figure as well as the force of theChinese writing brush to change the thickness of strokes. The area thegeometric figure through is the strokes of a character. The geometricfigure may be a circle, an oval-shaped, a rectangle, a square, or theother different form (e.g. irregular-shaped). Referring to FIG. 4A-FIG.4C, one preferred embodiment of this invention employs a circle 28 todescribe the thickness in strokes. In fact, the area of a character 30should fill with colors, but the area of a character is replaced fillingcolors by oblique lines in the drawings. The step thereof comprises:

[0026] 1. In accordance with the characteristic of strokes of character30, the moving paths 26 in the center of circle 28 and coordinates ofthe starting control points 20, control points 24, and ending controlpoints 22 are decided.

[0027] 2. In accordance with the thickness of a starting point and aending point of the strokes, dimensions of the circle 28 for startingcontrol points 20, control points 24, and ending control points 22 aredecided.

[0028] 3. A center of circle 28 moves along the moving path 26 and thedimensions of circle 28 is changed with a function. The function isdecided according to the variant of thickness in the strokes.

[0029] 4. Character 30 is the area the circle 28 moves through.

[0030] Step 1: Referring to FIG. 3, in accordance with thecharacteristics of the strokes in the character, the moving path 26 ofcircle 28 and the coordinates of the starting control points 20, controlpoints 24, and ending control points 22 are decided. The moving path 26is described by, one order function, two order function, three orderfunction or other order functions that can best describe the moving path26. One order function needs the coordinates of one starting controlpoint 20 and one ending control point 22. Two-order function needscoordinates of one starting control point 20, one ending control point22, and one control point 24. Three order function needs coordinates ofone starting control point 20, one ending control point 22, and twocontrol points 24, and so on. For example, a moving path 26 is describedby a three-order function, as shown in FIG. 4A:

x(t)=a ₃ t ³ +a ₂ t ² +a ₁ t ¹ +x ₀  (1)

y(t)=b ₃ t ³ +b ₂ t ² +b ₁ t ¹ +y ₀ tε[0,1]  (2)

[0031] where a₁=3(x₁−x₀)

[0032] a₂=3(x₂−x₁)−a₁

[0033] a₃=x₃−x₀−a₂−a₁

[0034] b₁=3(y₁−y₀)

[0035] b₂=3(y₂−y₁)−b₁

[0036] b₃=y₃−y₀−b₂−b₁

[0037] Due to the function being a three order function, it needs thecoordinates of four points: (x₀, y₀)˜(x₁, y₁)˜(x₂, y₂)˜(x₃, y₃), wherein(x₀, y₀) the coordinate of the starting control point 20 of the movingpath 26; (x₃, y₃) is the coordinate of the ending control point 24 ofthe moving path 26; (x₁, y₁) and (x₂, y₂) are the coordinates of controlpoints 22 of the moving path 26. Moreover, the control points 24 are notnecessarily on the moving path 26. When t is the parameter forcontrolling the moving path 26, its range is 0 to 1. If t is 0, x(0)=x₀,y(0)=y₀, i.e. the coordinate of the starting control point 20, and t is1, x(1)=x₃, y(1)=y₃, i.e. the coordinate of the ending control point 24.Therefore, the path of the coordinate (x(t), y(t)) during t being 0 to 1is the moving path 26. The variants or bends of the moving path 26 canbe controlled by changing the coordinate (x₀, y₀), (x₁, y₁), (x₂, y₂),and (x₃, y₃) the starting control point 20, control points 24, andending control point 22. Then, the moving path 26 can be described byEq. (1) and (2).

[0038] Step 2: In accordance with the thickness of a starting point andan ending point of strokes, the dimensions of the starting controlpoints 20, control points 24, and ending control points 22 are decided.When a stroke is thick, the circle 28 is bigger, and when a stroke isthin, the circle 28 is smaller. The radiuses, that are ro of circle 28of the starting control point 20, r₁ and r₂ of the circle 28 of thecontrol point 24, and r₃ of the circle 28 of ending control point 22,are decided according to the stroke characteristic.

[0039] Setp3: The center of the circle 28 moves along the moving path 26and the radius of the circle 28 changes with a function. The function isdecided according to the variant of thickness in the strokes. Inaccordance with the characteristic of the thickness of differentstrokes, the variant of strokes can be described with differentfunctions. For example, a function of the radius of the circle 28 isdescribed below:

r(t)=(r ₃ −r ₀)t+r ₀ε[0,1]  (3)

[0040] where r₁ and r₃ are the radius of the circle 28 at startingcontrol point 20 and ending control point 22. The t is a parameter andits range is 0 to 1. When t is 0, r(0)=r₀, i.e. the radius of the circle28 at starting control point 20, and t is 1, r(1)=r₃, i.e. the radius ofthe circle 28 at ending control point 22. Therefore, the radius r(t)during t being 0 to 1 is the radius of the circle at the coordinate(x(t), y(t)). The Eq. (3) describes that a stroke gradually becomesthick or thin.

[0041] The other function is described below:

r(t)=c ₃ t ³ +c ₂ t ² +c ₁ t+c ₀ tε[0,1]  (4)

[0042] wherein c₁=3(r₁−r₀)

[0043] c₂=3(r₂−r₁)−c₁

[0044] c₃=r₃−r₀−c₂−c₁

[0045] The r₀, r₁, r₂, and r₃ are the radiuses of circle 28,respectively. The radiuses of r₁ and r₂ depend on the coordinate (x₁,y₁) and (x₂, y₂) of the control points 24 and are decided according tothe thickness of the strokes. The t is a controlling parameter and itsrange is 0 to 1. When t is 0, the r(0)=r₀, i.e. the radius of circle 28at the starting control point 20, and t is 1, the r(1)=r₃, i.e. theradius of circle 28 at the ending control point 22. The radius r(t) isthe radius of circle 28 at the coordinate (x(t),y(t)) of moving path 26during which t being 0 to 1. Eq. (4) describes a stroke with threetransitions of thickness at most.

[0046] Referring to FIG. 4B, when the center of the circle 28 movesalong the moving path 26, the variant of the radius of circle 28 isdecided by substituting t of the radius r(t) for the coordinate(x(t),(y)t).

[0047] Setp4: Referring to FIG. 4B, the character 30 is the area whichcircle 28 moves through.

[0048] The moving path 26 can be separated by a plurality of moving path26 if the moving path 26 has complicated transitions, especially at thestarting or ending portions of a stroke. Then starting control points20, control points 22, and ending control point 24 of the moving paths26 are decided. The moving paths 26 may be not connected with eachother, i.e. starting control point 20 of one of the moving paths 26 maybe not ending control point 22 of the other moving path thereof.Referring to FIG. 4D, the stroke is accomplished refined and beautifullyaccording to steps 1 to 4.

[0049] Referring to FIG. 5A, a character 30 is separated several movingpaths 26 and the complicated sections can be separated several extramoving paths 26 in accordance with steps 1 to 4. The circle 28 movesalong the moving paths 26 and is changed the radius of the circle 28.The character 30 is the area the circle 28 through. The accomplishedcharacters 30 are as shown in FIGS. 5B, 5C, and 5D.

[0050] In the present invention, due to the Chinese writing brush fontdata, the coordinates of the starting control point 20, control point24, and ending control point 22 of each moving path 26 and theparameters from the radius r(t) of circle 28. The amount of data in thepresent invention is less than the amount of data of the outlined fontand close to or slightly more than the amount of data of the vectorfont. For example, referring to FIG. 6A, is a stroke of “

”. This stroke needs 45 points of starting control points, controlpoints, and ending control points by means of the outline font.Referring to FIG. 6B, the stroke is separated by four moving paths 26,of the Chinese writing brush font of the said present invention, whereinstarting control points 20 of three moving paths 26 are ending controlpoints 22 of the other moving path 26, respectively. Therefore, thestroke has eight points consisting of, starting control points 20,control points 24, and ending control points 22. Referring to FIG. 6C,the stroke further needs eight radiuses of r₀, r₁, r₂, and r₃ fordescription. According to one datum is 8 bits, a coordinate (x,y) needstwo data, i.e. 16 bits, and one radius needs one datum, i.e. 8 bits.Hence, in the example, it needs totally 45×16 bits=720 bits by means ofthe outline font, and the present invention needs 8×16 bits+8×8 bits=192bits, so that the needed data of the present invention is one of fourthof the data of the outline font.

[0051] Referring to FIG. 6D, a whole character, “

”, needs totally 70 points of starting control points 20, control points24, and ending control points 22. Due to too the fact that many pointswill cause a complicated figure, it omits control points 24. Referringto FIG. 6E, the Chinese writing brush font of the present inventionneeds 15 points (comprising of a starting control points, controlpoints, and ending control points). Referring to FIG. 6F, it needs 9points (comprising of starting control points, control points, andending control points), by means of the vector font. Therefore, the fontdata of the present invention is greatly less than the outline font dataand slightly more than the vector font. Moreover, the Chinese writingbrush font only needs extra data in the radius, i.e. the radiuses r₀,r₁, r₂, and r₃ the starting control points, control points, and endingcontrol points data, a total of 15, to describe the variant of thicknessof the character. Referring to FIGS. 6G and 6H, the vector font is onlydecided a lightface or boldface and can not describe the variant of thethickness of strokes.

[0052] Table. 1 shows the amount of data for the outline font, thevector font, and the Chinese writing brush font of the presentinvention. In general, the amount of data in the outline font is about 5to 12 million bytes and the amount of data for the vector font is about0.2 to 12 million bytes. Hence, the ratio for the amount of data for thevector font and the outline font is about one fourth to one twentieth.TABLE 1 The amount of data (Million Bytes) Outline Chinese WritingVector Font Font Font Brush Font (Stroke-based font) Data 5-12 0.5-3  0.2-1.2 Ratio (Compared 1/4-1/20 1/10-1/50 with outline font)

[0053] Therefore, the amount of data for the Chinese writing brush fontis similar to the amount of the data for the vector font and less thanthe amount of the data of the outline font. Moreover, the characterdescribed with the Chinese writing brush font is refined and beautifullysimilar to the outline font.

[0054] The character displayed in different sizes can be described bymodulating the coordinates of the starting control points 20, thecontrol points 24, and the ending control points 22 of the moving path26 with a ratio of equality. The radiuses r_(i) (i=0, 1, 2, . . . ) ofthe circle 28 may be modulated with the ratio of equality or a differentratio.

[0055] Furthermore, the present invention may be employed with thecomposing font, i.e. a character 30 formed by composing the basicstrokes of the character. The character is composed with the data of theneeded basic strokes and positions of the strokes. In accordance withstrokes of the character stored in a database and the positions of thestrokes, the character is composed by modulating the size of the strokesaccording to the size of the character. Hence, the data of the composingfont are only the same strokes of the characters 30 described by meansof the Chinese writing brush font and the relative position of strokesin the characters. The amount of the data of the composing font is lessthan the amount of the data comprising total characters. The charactercomposed by the basic strokes of the composing font can be described bymodulating the coordinates of the starting control points 20, thecontrol points 24, and the ending control points 22 of the basic strokeswith a ratio of equality. The radiuses r₁ (i=0, 1, 2, . . . ) of thecircle 28 may be modulated with the ratio of equality or a differentratio.

[0056] According to the preferred embodiments, this invention disclosesdescriptive method of characters for displaying the thickness of strokesthereof. According to descriptive method of characters of the presentinvention, the amount of data is less than the amount of data for thebitmap font and the outline font and is close the amount of data for thevector font. Furthermore, it can describe the character as the outlinefont and does not have the disadvantages of the vector font that can notdescribe the character in a refined and beautiful manner. Moreover, itavoids the disadvantages of distortion of the resized characters and cankeep the refined form from modulating the size of the characters easily.

[0057] Although specific embodiments have been illustrated anddescribed, it will be obvious to those conventional art that variousmodifications may be made without departing from what is intended to belimited solely by the appended claims.

What is claimed is:
 1. A descriptive method of font for displaying athickness of at least one stroke of at least one character by means of ageometric figure, said method comprising the following steps of:deciding at least one moving path of said character according tocharacteristics of said at least one stroke, deciding a dimension ofsaid geometric figure at a plurality of control point according tocharacteristics of a thickness of said at least one stroke; and moving acenter of said geometric figure along said least one moving path andvarying said dimension of said geometric figure to form said character.2. The descriptive method of font according to claim 1, wherein saidgeometric figure is a circle.
 3. The descriptive method of fontaccording to claim 1, wherein said geometric figure is selected from thegroup consisting of a oval-shaped, a rectangle, a square, and a regularpolygon.
 4. The descriptive method of font according to claim 1, whereinparameters of said moving path comprise coordinates of a plurality ofsaid control points.
 5. The descriptive method of font according toclaim 1, wherein variants of said dimension of said geometric figure isdescribed by first or more order function.
 6. The descriptive method offont according to claim 1, wherein said character is selected from thegroup consisting of Chinese characters, Japanese characters, and Koreancharacters.
 7. The descriptive method of font according to claim 1,wherein said at least one moving path is described by first or moreorder function.
 8. The descriptive method of font according to claim 1,wherein a method of modulating the size of said character comprises:modulating said coordinates of said a plurality of control points ofsaid at least one moving path of said at least one stroke with a ratioof equality; modulating said dimension of said geometric figure of saida plurality of control points of said moving path with said ratio ofequality; and moving a center of said modulated geometric figure alongsaid modulated least one moving path and varying said dimension of saidmodulated geometric figure to form said character.
 9. The descriptivemethod of font according to claim 1, wherein a method of modulating thesize of said character comprises: modulating said coordinates of said aplurality of control points of said at least one moving path of said atleast one stroke with a ratio of equality; maintaining said dimension ofsaid geometric figure of said a plurality of control points; and movingsaid center of said geometric figure along said least one moving pathand varying said dimension of said geometric figure to form saidcharacter.
 10. A method of composing font, said method comprising thefollowing steps of: forming a database comprising of at least one commonbasic stroke of at least one character; wherein a descriptive method ofsaid at least one common stroke of said at least one character of saiddatabase comprising: deciding at least one moving path of said characteraccording to characteristics of said at least one common basic stroke ofsaid at least one character of said database, deciding a dimension ofsaid geometric figure at a plurality of control point according tocharacteristics of a thickness of said at least one basic stroke; andmoving a center of said geometric figure along said least one movingpath and varying said dimension of said geometric figure to form saidcharacter.
 11. An apparatus of descriptive font, comprising: an assemblydeciding at least one moving path of said character according tocharacteristics of said at least one stroke, an assembly deciding adimension of said geometric figure at a plurality of control pointaccording to characteristics of a thickness of said at least one stroke;and an assembly moving a center of said geometric figure along saidleast one moving path and varying said dimension of said geometricfigure to form said character.